Produced Water Filters

Problem: A small independent operator generated a large volume of waste filters from a produced water injection system for a water flood. About 14,000 barrels of produced water is reinjected each day. Two produced water filter units at 36 injection wells were replaced twice per month resulting in about 1,700 waste filters per year. The operator spent $4,148 per year for new replacement filters ($2.44 per filter x 1,700 filters). Additional expense was incurred from waste filter management and maintenance.

Solution: The operator changed the procedure by basing replacements on differential pressure rather than on a twice-monthly schedule. Valves were installed on filter inlet and outlet to accommodate a temporary pressure gauge hookup for differential pressure measurement. A capital investment of $1,800 was required for installation of the valves.

Benefits: The operator's procedure change and simple equipment modification resulted in a significant reduction in the volume of waste filters. In the year following the change, a total of 28 waste filters were generated. The change was very cost effective due to reduced maintenance requirements, reduced waste management, and reduced filter replacements. The operator saved about $4,000 per year due to the reduced filter replacement costs. The capital investment was recovered in about five months, based only on the reduction in new filter costs. Additional savings were gained from the reduced maintenance and the reduced waste management.